Such a damper is disclosed e.g. in EP 1303710. Dampers of this kind may be used to dampen vibrations with one or more target frequencies. For instance, the damper may be installed in the steering wheel of a vehicle, and may be used to dampen vibrations in the steering wheel corresponding to the idling rpm of the vehicle. One technical issue associated with such dampers is how to make them useful for combating vibrations of various kinds.